The lockers typically used in athletic locker rooms and schools include a door that is hinged on either the right or left side and that includes a latch and/or lock mechanism. The door is made of a sheet of metal that is either solid or mesh. The door is secured in the closed position by the latch mechanism and lock. In many lockers, a combination lock is used, and the latch mechanism and the lock are combined into a single mechanism. In these lockers, the door is held in the closed position by an extensible bolt that engages behind a strike in the frame of the locker.
In general, there are two types of bolts, automatic spring loaded bolts and manual dead bolts. Gym and school lockers usually contain a spring loaded bolt. A spring loaded bolt, when in an extended position, can be forced back into the lock case from which it extends simply by pushing on the end of the bolt. This type of bolt has a tapered side so that when the door is pushed closed the tapered side hits against the strike in the door, pushing the bolt into the lock case. When the bolt clears the strike, it once again extends. A straight surface of the bolt opposite the tapered surface engages the area behind the strike such that the door can only be opened upon rotation of the internal mechanism of the lock upon proper sequencing of the combination. Therefore, a locker having a spring loaded bolt provides the benefit of being able to close the door without first pulling the bolt into the case. The spring loaded bolt also contributes to one of the drawbacks of these lockers. Even when the door is closed and the bolt is disposed behind the strike, if one can access the bolt and push on it, the bolt will move into the housing, defeating the lock. Lockers with mesh type doors are particularly susceptible to this type of attack.
By contrast, when a deadlocked bolt is in the extended position, it cannot be pushed back into the housing by means of an applied external force. The bolt is said to be dead, hence the name dead bolt. This type of bolt solves the drawback of the spring loaded bolt being defeated by an applied external force even with the door closed. However, a locker having a dead bolt type lock cannot simply be pushed closed with the bolt in the extended position. The bolt must first be retracted by use of the combination mechanism and sometimes extended by using the combination mechanism again once the door is closed. This makes opening and closing the locker quite cumbersome.
Attempts have been made to combine the benefits of both of these bolt types in latches used in conventional entry way doors. For example, U.S. Pat. No. 5,516,160 is directed to automatic deadbolts. This patent discloses a lock having a bolt cooperating with a wire the end of which is disposed in a complex series of slots, ramps, and walls within the side of the bolt. A plastic clip retains the end of the wire in operative contact with the bolt. The bolt can be positioned in an inserted position, fully extended dead bolt position, or an intermediately extended automatic bolt position based upon the path of the end of the wire through the slots, ramps, and walls. As such, only the bolt itself is needed to direct movement from the intermediate position to the fully extended position. Separate mechanisms within the lock, however, are needed to position the bolt in the inserted position and to secure the bolt in the fully extended position.
U.S. Pat. No. 5,918,916 is directed to an automatic deadbolt having a separate plunger. This patent discloses a lock in which the bolt automatically extends to its full deadlocking position when the door is closed. According to this patent, a plunger mechanism is included and placed on top of the bolt such that contact between the plunger and the door strike has the effect of automatically moving the bolt to its fully extended position. The bolt also includes a pair of stop members pivotally attached thereto. The stop members each have a pin that engages one of two cam tracks in the plunger and co-acts with the plunger such that relative movement between the plunger and the bolt causes the stop members to pivot between extended and retracted positions. In the extended position, the stop members engage stakes on each side of a front case of the lock to prevent outward movement of the bolt beyond the intermediate extended position. In the retracted position, the bolt cannot be held by the stakes and is permitted to move to its fully extended position. Inward movement of the plunger is limited by contact with the front plate of the lock. Outward movement of the plunger is limited by either contact between the bottom projection of the plunger and the front wall of a track in the top of the bolt or contact between the plunger and the door strike. Like the device of the previously mentioned patent, separate mechanisms within the lock are needed to position the bolt in the inserted position and to secure the lock in the fully extended position.
In addition, the automatic bolt combination locks used on lockers are supplied with one factory combination and four addition combinations for a total of five combinations. By inserting a key into the combination dial and rotating while at the same time pushing a button extending from the back case of the lock, the current combination setting can be moved sequentially through the four alternative combinations. Should an object within the locker fall against the button, then the combination lock could fail to operate properly. In addition, the sheet-like metal of the door is significantly thinner than the lock case causing it to protrude from the inside surface of the door. Given that many gym and school lockers have narrow doors and correspondingly short pivot radiuses, the lock case can contact the strike if not positioned back from the edge of the door. However, moving the lock away from the door edge also decreases the length of bolt that overlaps the door frame behind the strike, because the bolt is also moved inward from the edge of the door. This problem increases as the door width decreases and with locker doors having recessed pockets in which the combination locks are disposed.
In accordance with the present invention, a combination locker lock for mounting to the door of a storage locker is provided. The lock has a case and a bolt extending therefrom for engaging behind a strike in the locker frame. This bolt acts both as a spring loaded bolt and a dead bolt. To accomplish this dual functionality, the bolt has two extension positions, a fully extended position where the bolt acts like a dead bolt and a partially extended position where the bolt acts like a spring loaded bolt. The bolt can only be moved inward from its fully extended position upon entering the proper combination and rotating the combination dial. The two extension positions also enable greater bolt extension from the lock without requiring increased bolt thickness in order to accommodate a full-face taper.
When the bolt is in the partially extended position and the locker door is closed, the strike will push against a tapered surface on the bolt, pushing in the bolt into the case. A plunger associated with the bolt will also be pushed into the case. When the bolt passes the strike it will begin to extend from the case; however, the plunger, because of its positioning relative to the bolt, will contact the strike and will not extend from the case with the bolt. This induces relative motion between the plunger and the bolt, which permits the bolt to move to the fully extended position. A single trigger mechanism associated with the bolt and the plunger is used to hold the bolt in the spring loaded position, to secure the bolt in the dead bolt position, and to release the bolt to the fully extended position.
The combination lock can be quickly and easily flipped 180xc2x0 for both right and left hand locker door applications while maintaining the same set of combinations. The lock has a case with integral mounting flanges and a relieved edge adjacent the edge of the door, to permit the combination lock to be placed as close to the strike as possible even in narrow door applications. This maximizes the overlap length of the bolt behind the strike.
The lock has six different combination settings, one factory setting and five changes. The mechanism to change the combination is contained entirely within the lock case. In addition, the lock can be retrofitted onto existing lockers.